extra piece of placenta???????????

[ray4112005]

Ok this is really creeping me out. I am 33 wks and i went for my last ultrasound last week-the dr told me that there was an extra piece of placenta and showed me on my sonogram-its weird because i had never seen this before any other time-the dr told me that it was no big deal and that it was just something that i needed to let my dr know when its time to deliver so that they can be sure to remove it-she reassured me that it was nothing to worry about but when i chose to do my own research online i found some very scary information-this could be vasa previa which in those cases i think it said that the baby has a %50-%90 chance of survival-i know that i should not think this way but its hard not to-things can easily be mistaken as not a problem when really it is-i also read that it really could just be a piece of placenta and nothing more, but the weird thing is they said it is called a disappearing twin, meaning that at one point i couldve been pregnant with twins, this makes me extremly sad. Has anyone else been through this, i dont know what to think, i have a drs appt next week but just wanted to know if anyone could enlighten me on the situation, very scared right now